The present invention relates to a brake pressure control device of deceleration responsive type in which such an inertia-controlled valve element as a steel ball cooperating with a valve seat in a valve chamber to control the ratio of brake fluid pressures being applied to the front and rear wheel brake cylinders in response to the attainment of a predetermined rate of deceleration of the vehicle.
In a conventional pressure control device of this type, the pressure control is greatly influenced by the initial space between the valve element and seat, the flow of fluid acting on the valve element, the mass of the valve element, the supporting angle of the valve element, and the like. As well understood from the above-noted facts, it is very important to precisely set the valve element in position and control the flow of fluid acting on the valve element so as to ensure the optimum pressure control. Furthermore, in the case that the housing assembly for the control device includes first and second housing sections fluid-tightly fitted to each other to form the valve chamber therein, the initial setting of valve element is very difficult in assembly of the first and second housing sections.